Brake mechanism for railway cars



P. B. CAMP ET AL BRAKE MECHANISM FOR RAILWAY CARS Ayn 5, 1927.

Filed Dec. 6, 1924 3 Sheets-Sheet l [22 were 602 3:

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BRAKE MEGIiANISM FOR RAILWAY CARS Filed Dec. 6. 1924 3 Sheets-Sheet 2Z91 Ji I fiwi ggis fn enarq Aprifi 5 EQZF. 1,6233%4 P. B. CAMP ET ALBRAKE MECHANISM FOR RAILWAY CARS F iled Dec. 6, 1924- s Sheets-Sheet 515? We 72 taws: j mmy B. Caw/a Patented Apr. 5, 1927.

UNITED STATES PERCY B. CAMP, oE AYwooD, AND ACK wILsoN, or CHICAGO,ILLINOIS, ssIeNons To UNIVERSAL DRAFT GEAR ATTACHMENT 00., A CoRPon TIoNOF ILLINOIS.

BRAKE MECHANISM FOR RAILWAY C RS.

Application filed December 6, 1924. Serial No. 754,287.

This invention relates to brake mechanisms for railway cars and has for'its principal object tomaintain the slack in the foundation brake gearand the hand brake at a constant value; to adjust thehand brake tocompensate for-an increase in'slack in the foundation brake gear, and tomake the movement incident to applying the brakes by means of the brakecylinder, shorten the hand brake as the slack in the foundation brakegear increases.

Further objects and advantages of the; invention will become apparent asthe dis: closure proceeds and the description is read in connectionwiftlithe accompanying draw- 'ing illustrating a, selected embodiment ofthe invention, and in ='which Fig. 1 is a side-elevation of a carunderframe, illustrating a brake mechanism embodying the presentinvention, parts-being broken away;

Fig. 2is a plan view of the same; I

F igs." 3 and 4 are plan and side elevation of a' six-wheel truckequipped with clasp brakes;

Fig. 5 is a planview of an automaticslack adjuster for the hand brakeand one form of multiplying leverthat will first multiply the speed ofthe brake staff to quickly. take up the slack and then multi ly thepower of 'the brake staff to apply the rakes;

Fig. 6 is a side elevation of the same; Fig. 7 is an end view of theautomatic slack adjuster Fig. 8 IS a longitudinal sectional view of theautomatic slack adjuster; I

Fig. 9 is a plan view of an alternative f Fig. 10 is a partiallongitudinal sectional view-of the form shown in Fig. 9;

Fig. 11 is a partial transverse section taken on line 11-11 of Fig. 10,and

Fig. 12 is a pers ective view of the pawl used 1n the modifieconstruction.

The invention is particularly advantageous in connection with brakemechanisms-of the kind disclosed inthe patent to William H. Gleg No.1,558,840, issued Oct. 27, 1925, and Tor convenience is illustrated inconnec tion therewith.

Referring to Sheet 1, (Figs. 1, 2, 3 and 4) 10 indicates a conventionalbrake cylinder that operates the cylinder levers 11 and 12,

cooperating through the cylinder lever connection 13, to transmit powerof the'cylinder to the cylinder lever and floating lever con nections 14from which it is communicated to the floating lever 15 and, in'turn,through the rods 16, to the brake levers 17 which co:- operate withbrake levers 18 through the rods 19 and 20 to press the brake'shoes 21against the wheels 22. The cylinder lever 11 is fulcrumed at '23 on thepiston 25 of the cylinder, and the cylinder lever 12 is fulcrumed to amovable cross-head at 24 which is adjustably connected to the pres-vsure-head of the cylinder 10.

The hand brake includes abrake staff 26 adaptedto wind up a chain 27 andoperate a multiplying lever 28 carried in a jaw 29 suitably supported onguides 3O andconnected with. the hand brake lever 31 by the handbrakerod 32. i The hand brake lever is carried by a hand brake lever fulcrum33, mounted beneath the carand is attached to the foundation brakegear'in this instance by fastening it to the cylinder lever and floatinglever connection 14:. This connection has a sliding joint 34 whichpermits the hand brakeat one end of the car to apply,

the brakes to one truck without applying, them. to the other truck. r Inall types of brake mechanism wear 5 on the brake shoe increases theslack in the formation brake gear and in order to make the travel of thepiston in. the cylinder'10' substantially constant it is necessary tocompensate for this increase. of slack; This is done by what is known asa slack adjuster 35 (Fig. 2). which moves "the fulcium of the cylinderlever 12 to the left as the slack increases. The operation of thisdevice is well known and a description may be found g on page 841 of theCar Builders Encyclo pedla, 1922, published by Simmons-Boardm'anPublishing Co.

Heretofore, however, there has been no corresponding meansto make thethrow of the hand brake constant which becomes es-' pecially importantwith the devices for quickly taking up a given amount'of slac and thenchanging the mechanical advantage to apply the brakes with pressurecomparable to that of the air brakes. For example, in Figs. 5 and 6, themultiplying lever has a sector shaped arm 36 which receives the power ofthe brake stafi from the chain 27' and cooperates with theshorter arm 37anchored to the car by chain 38 to move the jaw 29 withspeed or power,as the case may be. This is fully-set forth in the patent to 'Clegg,above referred to, and it will suflice here to say that with the partsin the position shown in 'Fig. 6, a slight'movement of .the chain. 27will revolve the lever through 90, during which movement it multipliesthe speed and takes up the slack, then upon further movement of thechain 27 the multipklying lever rotates slowly, and multiplies t bplyinglever, the efficiency of the device is and the motion incident toapplying the reduced and the time necessary for applying the brakes iscorrespondingly increased.

According to the present invention the slack is maintained at 5substantially constant value by shortening the hand brake brakes withair ressure is used to make the compensating adjustment.

In the construction shown in Figs. 5, 6, 7 and 8, Sheet 2, the jaw 29 isequipped with a guide 39 of hexagonal cross section with in which is arack 40'of similar cross section having teeth 41 on\its 'upper facesfor. cooperation with a pawl 42, housed in a pocket 43 on top of theguide.

In all brake mechanisms the hand brake is operatively connected with thefoundation brake gear and some of its parts move each time the brakesare applied by the air pressure. In this instance each application ofthe brakes 'by'the air pressure rocks the hand brake lever 31 and:reciprocates the hand brake rod 32. Byconnecting the rack 40 to thishand brakerod therack is made to partakeof that movement. When-thetravel of the piston does not exceed the normal the rack 40 will merelymove to the right 8) in the guide 39, and then back again to thepositionshown, the pawl 42 traveling withthe'rack without releasing it. However,should the Wear on the brake shoes cause the piston travel to exceed thenormal, the rack would move further to the right and the pawl 42, comingin contact with the wall 44 of the pocket 43, would be checked. If

' the rack 40 continues to the right the width of one tooth 41, the pawlwill ride upwardly in the ocket 43 and drop into the next set ofnotches. Then, when the brakes are released and the parts assume theirnormal slack position, the hand brake will be shorter by the width ofone tooth 41. Subsequent brake'ap lications will produce a reciprocationof t e rack and pawl without changing their engagement until the slackincreases sufiicient y to let the rack move beyond the normal width ofone tooth, when another compensating adjustment will take place.

I This will continue until the brake shoes are worn down to the pointwhere replacement is necessary.

By inclining the upper wall '45 of the pocket 43 the pawl 42 isautomatically locked in engagement with the rack when any stress is tobe transmitted and is permitted to release the rack by riding up theinclined faces of the teeth 41 when an adjustment is to be made. Inorder to restorethe pawl to normal position at the right end of the rackwhen new brake shoes are put in, the rack is pushed to the rightmanually and the pawl is raised and the rack slid back to the left andthe pawl lowered. The position of the pawl is controlled manually by theU-shaped yoke pivoted at 46 having one arm '47 serving as a handle,while the other arm 48,.extends through the pawl. v

The right 'end of the guide is equipped with a stop 49. For conveniencein manufacture this stop maybe cast integral with the guide. The upperand lower faces of the rack conform to the corresponding faces intheguide, but the lateral faces of the rack are shorter than thecorresponding faces on the guide which results in ample clearancebetween the teeth and the upper portion of the guide. This difference insize also makes possible the assembly of the guide and the rack. Theside of the guide next to the arm 36 ot' ,the multiplying lever is cutaway along the line 50 (see Figs. 5 and 7). By tilting the rack to theleft in Fig. 7 it may be-i'nserted, into the guide past the stop 49...In the form shown in Fig. 8 the rack 40 is threaded to the rod 32, asshown at 51, and the guide and rack are provided with aligned openings52 and 53 to permit the operator to see when the threaded engagement iscomplete.

In the alternative form illustrated in Figs. 9, 10, 11 and 12, Sheet 3,the brake rod 32 extends through an aperture 54 in the end of a rack 55which is provided with a chamber 56, receiving a nut or collar 57 on theend of the rake rod and permitting it free relative movement of thelength corres onding to the normal piston travel. The rac is mounted ina guide 58, similar to the guide 39, and for convenience they areprovided with. aligned openings 59 and 60 through which the nut 57 maybe inserted in assembling. The pawl 61 is pivoted at 62 in anenlargement of the guide and carries at its free end a pivoted jaw 63,having teeth 64, for cooperation-with the corresponding teeth 65 on therack 55. The guide is provided with longitudinal flanges 66 connected byreenforcing ribs 67 to give it ample strength to withstand the thrust onthe pawl.

In this construction a normal piston travel merely causes the nut 57 onthe brake rod 32 to move forward and back in the chamber 56. Anyadditional piston.travel will re-,

roe

sult in the nut strikin the rear wall 68 of the chamber 56 and t erack'will begin to move to the right in Fig. 10. Ifthis movementcontinues for the length of a tooth 65, the pawl will drop intothe nextspace between teeth and thus shorten the hand brake Use has been made ofspecific description and illustration in order todisclose the invention,but it is intended that nothing contained herein shall unnecessarilylimit the followin claims, or require a construction thereof t at wouldpermit the substance of the invention to be usedwithout infringe ment. Q

We claim as our invention: a

1. In a brake mechanism, the combination of a foundation brake gear, abrake cylinder for operating the foundation brake gear, and a hand brakefor operating the foundation brake gear, including a hand power deviceand means connecting the hand power device and the foundation brake gearautomatically operable to adjust the hand brakedurin the brake applyingmovement of the foun ation brake gear by air to compensate for slack.

.2. In a brakemechanism, the combination of a foundation brake gear, abrake cylinder for operating the foundation brake gear, and a hand brakefor operating the foundation brake gear, including relatively movableelements operated when the brakes are applied by air pressure to adjustthe hand brake to compensate for slack in the foundation brake gear.

3. In a brake mechanism, the combination of a foundation brake gear, abrake cylinder for operating the foundation brake gear, and a hand brakefor operating the foundation brake gear, including an element movingwith the foundation brake gear when the air pressure is applied and asecond element co operating with said moving element to shorten the handbrake to compensate for slack in the foundation brake gear when themovement of the first element under the action of the air pressureexceeds a predetermined amount. t

4. In a brake mechanism, the combination of a foundation brake gear, abrake cylinder for operating the foundation brake gear, and a hand brakefor operating the foundation brake gear, including two elements one ofwhich moves with the foundation brake Qrection, whereby the hand brakeis autoinder for operat' gearwhen the air pressure is applied, and meanspermitting free relative movement of said elements in one direction andlimiting. the1r relative movement in the reverse d1- matically adjustedupon the movement of one element/with the foundation brake gear duringthe application of the brakes by, air.

5. In a brake mechanism, the combination of a foundation brake gear, abrake cylinder for operating the foundation brake'gear, and a handbrakefor operating the founda tion brake gear, including-3a rack and pawlmechanism operated by'tlie application of the brakes with air pressureto-shorten the hand brake.

6. 'In a brake mechanism, the combination of a foundation brake gear, abrake cylinder for operating the foundation brake gear, and a hand brakefor operating the foundationbrake gear including a rack moving when theair pressure is applied, apawl cooperating with the rack upon excessmovement of the rack by'the air pressure to automatically adjust thehand brake to compensate for slack. 7. In a brake mechanism, -thecombination of a foundation brake *gear, a brake cyl-' the foundationbrake gear, and a handv rake for operating-the foundation brake gearincluding two elements one of which moves with the foundation brake gearwhen the same isoperated i by the brake cylinder and means ermittingfree relative movement of said e ements in both directions within aselected range of travel, but curtailing the reverse movement when thatrange is exceeded. I

- 8. In a brake mechanism, the combination of a foundation brake gear, abrake cylinder, 9. piston-in the brake cylinder connected with thefoundation brake gear, a hand brake for operating the foundation brakegear, including means operated by the movement of the piston during anair brake application to automatically adjust the hand brake to compensate for slack when the piston exceeds its normal traveL- 9. In abrake mechanism, the combination of a foundation brake gear, a brakecylin-- der, a piston in the brake cylinder connected with thefoundation brake gear, a hand brake for operating the foundation brakegear, including two relatively movable elements, one of which isconstrained to travel with said piston, and means to shorten the reversemovement of the last mentioned eleoperating the foundation brake gear,inclu'd mg means to take up the slack quickly and then apply the brakingpressure, and means to shorten the hand brake to compensate for and thenapply the braking Eressure, and an increase of slack in thev foundationmeans for maintaining the slac in the hand 10 brake ear. 7 1 brake andfoundation brakegear substan- I 11. a brake mechanism, a foundationtially constant.

5 brake gear, a brakecylinder for operating- In testimony whereof weaflix our signathe foundation brake, gear, a handbrake for tureaoperating the foundation brakegear, in- PERCY B. CAMP. eluding means totake up the 'slack quickly JACK WILSON.

